Internal-combustion engine



April 28,' 1931. M. BRAU INTERNAL COMBUSTION ENGINE Patented Apr. 28,1931 PATENT OFFICE MARCEL BEAU, OF RIVESALTES, .PYRENEES-ORIENTALES,FRANCE INTERNAL-COMBUSTION ENGINE Application filed May 2, 1929, SerialNo. 359,932, and in France May 12, 1928.

This invention relates to internal combustion engines of the class inwhich cylinders are arranged parallel to the axis of the engine and thepistons coact with the shaft through connecting rods and a cam drum onthe shaft so arranged that there are two complete reciprocations perrevolution. The principal object of the invention is to construct anengine in which fixed cylinders are used which can easily be mounted orremoved for repairs or to enable the power of the engine to be alteredwithin Wide limits without affecting the balance 1n any way.

One preferred embodiment of the invention is illustrated in theaccompanying drawings, but it will be understood that considerablevariation may be made without departing from my invention which isparticularly defined in the appended claims.

In the drawings,

Figure l is a longitudinal section taken on the line II of Figure 2, onecylinder group being omitted. I

Figure 2 is a plan, partly in section of-the engine, and

Figure 3is a developed View of the cam drum carrying the driving cam andthe distributing came.

In Figure 2 it will be seen that the central casing of the engine is ofpolygonal form, eachside being adapted to receive a group comprising apair of cylinders. 1 As shown only two groups of cylinders are mounted,the upper group being shown with the cylinder head in position and thelower group partly in section so as to show the interior of the casing.

In the engine shown by way of example in the drawings the polygonalcasing has six sides so that the engine can have any even number ofcylinders up to twelve.

The central casing 1 is a regular hexagonal right prism, each face 2being adapted to receive a group of opposed cylinders 4 and 5 which aresecured to the casing 1 by studs and nuts 6. The-cylinder group is cutaway substantially diametrically where it is secured to the casing 1 ascan be seen in Figure 2, the ends of the casing being recessed at 8 toclear the piston skirts. When any side of the casing is not used tosupport a cylinder, the casing is closed on that side by a plate 7having exten sions which cover the ends of the corresponding recess 3.Each end face is provided with six bores 8 arranged circumferentiallywhich form or receive guides for the tappets 9 for actuating the valverockers 10. The casing ends are also provided with suitable bearings 25to take radial and end loads, for the main shaft 16, a screw device 26for adjusting end playand a gland 27 and packing 28 for retaining oil.

The drive drum 11 is a cylinder in the face of which is formed as bymilling a sinusoidal guideway of such pitch as to cause four pistonstrokes per revolution, that is one stroke for each 90 of rotation ofthe shaft.

On each end of the drum 11 is circular cam having a profile comprising aprojectlng part 13, a flat part 14 and a hollow part 15. These camscontrol the distributing valves 29, 36 through the tappe'ts 9, push rods30 and rockers'lO, and are set in relation to the guideway 12 much asshown in the development in Figure 3, to give the correct valve timing.Contact between the tappet and the cam is-maintained by a return springas at 38 which must be stronger than the spring of the valve 36.

The main shaft 16 transverses the drum 11 axially and the two arerigidly connected together for example by a conical seating 31 and nut32 which may be looked, a key 33 being provided if desired for extrasecurity.

The opposed cylinders such as 4 and 5 in each group may have theirbarrels in a single piece, being made from a bored tubular body closedat each end by a head secured by studs and nuts 6a. Each group of twocylinders is provided with a connecting rod 18 attached at each end to apiston 19. At the centre of the connecting rod is a boss 20 whichreceives a spindle 21 which may be cast or screwed in, and which carriesat one end aroller bearing 22 and at the other a rectangular section die23 which runs in a longitudinal guideway 24 mounted in the side of thecylinder body thus preventing any rotational movement of the connectingrod about its axis. Each cylinder head 17 is provided with two passages34, 35 one for admission, the other for exhaust, closed by the valves29, 36 actuated by the rocker 10 as above mentioned. An additionalopening 37 (Fig. 2) is provided to receive a sparking plug.

The complete engine can be assembled as follows. The main shaft 16 issecured in the drum 11, placed in the casing 1, the bearings fitted inposition, the two parts of the case firmly fastened together, the endplay adjusted and the oil packing devices fitted.

Each cylinder group is assembled by bolting in the guide 24, insertingthe connecting rod and pistons in the cylinder body so that the die 23enters the guideway, and finally securing the cylinder heads.

The required number of cylinder groups are then secured to the casing,the roller devices 22 being entered into the guideway in sodoing. Theclearance in the valve gear is set andfinally those recesses 3 in whichcylinders are not mounted .are closed by the covers 7.

Once assembled the valve timing is automatically set and remains sopermanently. Ignition current may be supplied by any suitable separatemeans and by mounting the distributor in a definite position on theshaft 16 say by keying or on the drum 11 the ignition timing will alsobe automatically set.

Naturally suitable exhaust and inlet manifolds and fuel supply means ofany suitable construction are provided.

If now the shaft 16 be rotated, the drum 11 also rotates and the pistonswill be reciprocated in the cylinders through the guideway 12, rollers22 and connecting rods 18. The piston stroke obviously depends on theaxial length of the guideway 11. Considering any one piston startingfrom the inner end of the stroke, the corresponding tappet 9 will beheld down in the hollow 15 by the return spring 38, inlet valve 36 willbe open and the suction stroke takes place. After a rotation of theshaft through 90 the piston will be at the outer end of the stroke, thetappet 9 will have reached the level cam part 14 and the inlet valvewill be closed. During the next 90 the piston returns compressing thecharge. Towards the end of this stroke the charge is ignited, and thepiston is then driven downwards, driving the shaft 16 in so doingthrough the roller 22 and guideway 12. To-' wards the end of this strokethe tappet 9 is raised by the projecting part 13 of the cam and theexhaust valve 29 is opened. The piston then returns, driving out theburnt gases into the atmosphere.

From the end of this stroke the cycle recommences. It will be observedthat the distribution proceeds regularly round the circle and that thefiring order for the upper cylinders is 123-456. The lower cylindersfire in the same order but with a phase difference of 90 with respect tothe upper cylinders.

As above stated the example illustrated can operate with 2, 4:, 6, 8, 10or 12 cylinders all removable and interchangeable, without the engineneeding to be dismantled. To preserve balance it is advisable as far asp0ssible to remove and replace cylinder groups mounted on diametricallyopposite or other symmetrically disposed faces of the casing.

Further, the distributing cams being fixed with respect to the drivingdrum, the timing is fixed once and for all and cannot be upset.

This has the considerable practical advantage that assembly of theengine can be effected by anyone and the services of a specialist arenotrequired.

What I claim is 1. In an internal combustion engine of the classdescribed, the combination of a casing of right polygonal prismatic formhaving a seating in each side, a main shaft borne axially in saidcasing, a cylindrical drum on said shaft having a cam formed in. thecylindrical surface thereof, a cylinder secured in one or more of saidseatings with-its axis parallel with said shaft, a piston within eachsaid cylinder and means coupling said piston to said cam.

2. In an internal combustion engine of the class described, a casing, amain shaft borne .in said casing, a cylindrical drum on said shafthaving a cam formed in the cylindrical surface thereof, a one piececylinder group comprising a pair of cylinders in line secured to saidcasing with its axis parallel with said shaft, a piston in each of saidcylinders, a connecting rod joining said pistons and means coupling saidconnectin rod with said cam.

3. In an internal com ustion engine of the class described thecombination of a casing, a one piece body comprising a pair of cylindersin line having a fiat seating midway of its length between the cylinderswhereby it is secured to said casing, an externally detachable guidesecured to said body in its mid part, a plston in each said cylinder, aconnecting rod joining said pistons, a cross spindle screwed into saidconnecting rod, a die block on said cross spindle working-in said guide,a cam upon the engine shaft and a rollor on said cross member coactingwith said cam.

4; In an internal combustion engine of the class described thecombination of a casing having closable seatings thereon parallel withthe engine shaft, a plurality of cylinder bodies each comprising inonepiece a pair'of cylinders in 1ine secured in symmetrical arrangementonsaid casing seatings, a piston in each said cylinder, a connecting rodjoining the pair of pistons in each cylinder body, and a cam on theengine shaft coacting with said connecting rods.

In testimony whereof I have signed my name to this specification.

v MARCEL BRAU.

